Event
📍 Trébeurden
Pors Mabo, les plus vieilles roches de France
Dates
On 13 August 2026
In 75 days
In front of Pors Mabo beach in Trébeurden, these gneisses are the oldest dated rocks in France: 2 billion years old!
You can also see recent Quaternary formations: less than 100,000 years old.
Beware, walking on the foreshore is difficult.